Apparatus for heat treating strip metal



y 21, 1940- w. R. WEBSTER I 2,201,417

APPARATUS FOR HEAT TREATING STRIP METAL Filed June 3, 1937 INVENTOR .22 WM iizw BYW ATTORNEYS Patented May 21, 19.40

PATENT OFFICE,

APPARATUS FOR HEAT TREATING STRIP -METAL William R. Webster, Bridgeport, Conn. Application June 3,1937, Serial No. 146,153

3 Claims.

This invention relates to an apparatus for heat treating metal and more particularly for heating metal in strip form for annealing and similar purposes, such as described and shown in my earlier Patent No. 1,971,666, of August 28, 1934.:

As stated in the said patent, in producing brass and other cold rolled metal strips, it is necessary to heat the strip at intermediate stages and also as a final operation for the purpose of annealing it. To meet the requirements of the trade, it is essential that the metal be heated within very close temperature ranges in order to giveit the required properties.

In my said earlier patent the method consists of heating a metal strip to a uniform temperature by heating the wall of a rotary drum about the periphery of which the strip is passed, so that the strip lies in contact with the heated surface of the drum and is moved along with it as the drum is revolved. The drum is heated from the inside and the heat passes from its internal surface to its exterior surface, and by controlling the temperature of the exterior surface upon which the strip bears, and the speed at which the strip travels through its path or orbit, it is possible to obtain a nice control of the metal temperature, and it is also possible to heat all portions of the strip uniformly and in a manner which is convenient for the operator.

It is the main object of my present invention to improve the operation, construction and emciency of the apparatus described in my said earlier patent by the provision of means which will regulate the input of heat into the moving metal body depending upon the variations in the temperature of the metal itself.

This object is accomplished'as follows: By directing a heat responsive device, for example, a well known type of radiation pyrometer against the metal strip as it leaves the heat imparting medium, and by using this pyrometer or other heat responsive device in conjunction with an electric control device which also may be of well known construction and in conjunction with suitable speed changing means which may be 'of well known types, the speed of the metal strip can be controlled to regulate its temperature. In other Words, by this means the speed of the metal is made responsive to any variation in the final temperature of the metal.

I have found that by employing structure embodying the above named apparatus, the close regulation of the temperature of the heat impart;

ing medium itself requisite in my said earlier patent can be dispensed with. With this and other objects in view, my invention consists in the novel construction, combination-and arrangement of parts'as will be hereinafter more fully described and defined in the appended claims.

In the accompanying drawing in which similar reference characters denote corresponding parts:

Figure 1 is a'more or less diagrammatic side elevation of annealing apparatus constructed in accordance with my invention showing the application of speed changing mechanism to the heating drum;

' Figure 2 is a similar view of a modified form' of construction showing the application of speed changing mechanism to the pinch rollers used for feeding the metal strip;

Figure 3 is a similar view of another modified form of construction employing a stationary heating device and speed changing means in connection with the winding drum for the metal strip. Referring first to Fig. 1 of the drawing, A is a cylindrical drum of heat resisting material such as nichrome which has a flanged portion B at one side by means of which it is mounted on a suitably supported shaft (not shown), the shaft being fixed to the drum and adapted to rotate on suitable bearings (not shown). A burner H is supported in the interior of the drum. This burner may be of any suitable kind, but in the present instance it is shown as a gas burner supplied with gas and air through the pipes L and K respectively. Closing contiguous to the drum A are two rollers -E and E respectively which are arranged close together and whose axes are parallel to that of the drum A. The coil of metal N to beamnealed is mounted on a suitable support 0 and the strip from the coil is passed around the roller E, thence around the drum A, and thence around the roller E, from which it passes to a winding device or blocker I which is suitably driven from amotor J by a slip drive suchas belting or the like.

The burner H in the drum A presents a plurality of nozzles directed axially of the drum and located near its circumference at a number of points. Four of such nozzles are shown in the present instance. This burner structure is statfonary, and the drum A having the thin cylindrical Wall about which the strip is passed rotates about said burner structure. The burner structure by sending flames outward against or into close proximity to the inner circumference of the cylindrical strip-contacting wall, heats said wall to a uniform degree throughout the periphery of the drum.

By controlling the speed at which the drum A is rotated (in Fig. I) the temperature of the metal can be maintained within very close limits, and the softness of the metal as measured by the crystal size thereof controlled within exceedingly close limits which is a highly desirable result in this art.

In order to maintain a uniform'degree of contact between the strip and the surface of the drum, a tensioning device Q of any well known form is employed which is capable of being adjusted by means of a screw or wedge (not shown) Strip metal; of the character inquestio'n sometimes contains a certain amount of oil, the burnt products of which are apt to buildup on the surface of the drum so as to reduce the transmission of heat between the drum and the strip.

. To" prevent thisfa block of suitable abrasive 'strip pulling along the drum so that a given -point on the strip surface maintains contact with a given point on the drum surface until the stripportion in question passes to roller E'f.

In order to maintain the operation continuously, a duplicate of the support 0 (not shown) and a duplicate of the winding device I (not shown) are provided, and as the inner end of the coil is reached, the outer end of the succeeding coil is attached thereto by well known means. As the joint between the two coils reaches the device I, the two coils are separated by a shearing device (not shown) and the end of the second coil is wound on the duplicate winding device. f

In order to vary the speed of the strip for variation of the amount of heat imparted therea to by the drum A, I control thedriving speed of-the drum A as follows? A suitable heat responsive means as radiation pyrometexnP of well known type and construction is directed against the strip of metal preferably as it leaves the drum A.'- This pyrometer P is electrically connected 'as by wires I and 2 to a suitable electric balancing device H, such as for example, one commonly known in the industry as a "Micromax Electric Control which is a sensitive balance for regulating input in proportion to demand, and usually comprises an electric controller unit and a ,relay detector unit the two being diagrammatically illustrated at M and a reversible motor drive mechanism illustrated diagrammatically at If. These three which are electrically and mechanically interconnected combine to form a sensitive electrical balance. Any disturbance, due to a fluctuating,

in the condition being controlled (temperature here) is quickly detected resulting in immediate correcting movement of the motor drive mechanism P; In the embodiment of Fig. 1 the motor drive mechanism II of the electriccontrol device may be mechanically coupled through the worm it on its motor shaft: and the worm gear 13 to the regulating mechanism- M of a speed changing means G. The input shaft I5 of said means G is suitably driven as by a motor (not shown) and the output shaft 16 whose speed is varied in well known manner by the operation of. the regulating mechanism 84, which latter changes the efiective diameters of the belt connested pulleys on the two shafts by shifting opposing cone ases thereof (not shown) toward or away from each other in well known manner, serves to drive the drum A through a chain l5 and sprockets on shaft and the shaft of the drum A, or in any other well known manner.

dperation is as follows;

The controller device m by a suitable control setter HF thereon is set to the desired temperature of the metal strip. The radiation pyrometer P detects any change in temperature in the metal strip as it leaves the drum A, electrically transmits thischange to the electric balance II,

which being thereby-unbalanced, causes its mowhich frmctions without appreciable lag, will operate to increase the speed of the metal in its e aroimd the heated drum A. the other hand, should the temperature ofthe metal tendto .fall below the required point, the speed of the metal would be automatically reduced so that the metal absorbs more heatfrom the and its temperature consequently rises.

An alternative speed control for the metal strip is shown in Fig. 2 Herein a pair of driv ing pinch rollers F constituting strip feeding and unwinding means are applied to the strip between the roller E and the winding device or blocker I. These rollers F between which the strip passes are driven by a motor I! through a speed change mechanism Y. .As shown in this modification this mechanism Y includes a hollow input disk is and a hollow output disk 2|, the

first coupled to the drive .shaft of the motor I! and theother to an intermediate shaft it which latter suitably serves to drive the pinch or feeding rollers F through suitable gearing (not shown) and the chain drive II or' the like. Upon tilting of the. intermediate rolling disks 2! and 24 which bear on the surfaces of the disks I9 and 20 in the annular hollows thereof, the speed of the outputdisk It relative-to the input disk l9 may be regulated within desired limits. Tilting of said roller disks 23 and 24 is effected as follows: I

The shaft of the-motor drive mechanism II of the electric balancing unit II is provided with a crank 25, which latter through the link 26 is connected to the control crank 21 which is suitably coupled to the roller disks whereby movement of the crank 25 is transformed into tilting of the disks 23, 24. Operation in this modification is very similar to that of the first. The radiation pyrometer P detects any change in temperature of the metal strip. transmits thiselectrically to the electric balancing or control device i I which responds, its motor drive mechanism li operating the speed changer Y to regulate the speed of rotation of pinch roller 1i until normal required temperature conditions of the metalstrip are restored.

In the modification shown in Fig. 3, instead of passing the metal strip over a heating drum, I

'arm' 32 thereof is connected by the link 38 to the crank 25 of the electric control unit 11* 75 and the said arm thereby responds to movement of the crankZS The radiation pyrometer P is arranged contiguous to the point of exit of the strip from the heater furnace Z and detects variation in tem-' perature of the strip which it transmits to the electric control unit H which,.in turn, through the crank arm operates the rheostat 3| to regulate the speed of the motor and consequently that of the winding block I and the strip as it passes through said furnace, whereby thetemperature of said strip is maintained at the required point.

It is to beunderstoodof course that the spec changing mechanisms in any of the modifications may be interchanged; Thus, for example, I

the drive and speed change mechanism controlled as in Fig. 1 may be substituted for the rheostat controlled motor drive of Fig. 3 to operate the windingroller I and vice versa the controlled motor, drive 30 of Fig. 3 may be used to drive drum A of Fig. 1.

It is manifest, too, that the means of controlling the temperature of a moving substance to which heat is being applied is not applicable solely to the particular means of applying heat disclosed in my aforementioned patent or in the modifications above described. It is equally applicable even if the metal is heated for example by passing it between two electrical contacts,

which cause it to be heated by a current of elec-' tricity passing through the metal from one contact to the other, whether the current be direct or alternating.

It is also apparent, moreover, that various means can be employed for heating the drum A interiorly or exteriorly; for example, an electrical heater could be employed, or one using oil as fuel.

Further, it is also apparent that other types of electric control devices besides the unit herein very fine control of the crystal diameter of the metal strip, and it is also possible to secure uniform heating of all parts of a coil of strip metal. Furthermore, it is possible by the employment of relatively inexpensive apparatus to obtain uniform heating of all parts of large coils having many convolutlons, and this is a result greatly 1tiligslired by rolling mill operators at the present By use of a heat responsive means as a radiation pyrometer directed against strip of metal as it leaves a heating member, in conjunction with an electric control device and in conjunction with a speed changing device, the latter may be operated to control the speed of the drum A, the pinch rolls F or the winding block I By this means the speed of the metal is made responsive to any variation in the final temperature of the metal.

ment of strip metal and can be used for the treatment of wire and other materials.

Various changes may be made in the details of the apparatus, without departing from the scope of my invention as' defined in the claims What I claim 1. In a device for heat treating strip metal tric motor and said pinch rolls, and operated by said electric balancing motor drive whereby the speed of said pinch rolls and consequently the speed of said feeding strip is responsive to the heat of the strip itself, said variable speed device including a grooved input disk and a grooved output disk, the first coupled to said electric motor and the second connected through intermediate means to one of said pinch rolls, tiltable rolling disks engaging both said input and'output disks in the hollow portions thereof and means for connecting said rolling disks with said electric balancing motor drive to so tilt said rolling .disks in said groove whereby the speed imparted to said output disk by said input disk may be varied.

2. In a device for heat treating strip metal.

wherein a rotatable hollow body with heating means for said body located within the same around which body the strip to be heated is drawn in intimate contact are provided, means for drawing said strip over said body, means for driving said drawing means, a variable speed device interposed between said driving means and said drawing means, a temperature responsive detecting device located-adjacent the strip as it leaves the heating body and outside of the latter, an electric balancing motor drive controlled by said temperature responsive device and operating the variable speed device whereby the speed of said drawing means and consequently the feed of said stripis responsive to the heat of the strip'itself.

3. In a device for heat treating strip metal wherein a rotatable hollow body with heating means for said body located within the same around which body the strip to be heated is drawn in intimate contact are provided, means for directing the strip in immediate conductive contact'with the exterior of said body, gearing for rotating said hollow body, means for driving said gearing, a variable speed device interposed between said driving means and said gearing, a temperature responsive detecting device located adjacent the strip as it leaves the heatingbody and outside of the latter, an electric balancing motor drive controlled by said temperature responsive device and operating the variable speed device whereby the speed of said rotating body and consequently the feed of said strip is responsive to the heat of the strip itself.

WILLIAM R. WEBSTER.

ERTIFICA'TE 0F CORRECTION. I Petent No. 2301, 1 7. May 21,, 191w. f I R. WEBSTER, it is hereby certified. that error appeale the printedapecification of above numbered patent requiring cerrectiona's foliowsz Pege 1, secondeelun m, line 21, f "Closi read .-C1os elypage first column, line 67, before "which" insert a parenthesis line Tug-after "manner"- insert eperenthes-is page 5, firs't columh,,f1ine 51, fer "is is readit 13- second coluim z, line 35, claim 1, fer "gro 0ve'.' read --g rooves'-;

and that the said Letters Patent hould be read w'itli this, eorrection therein that the seine may coni orm to the record of the case in the Patent Office. I and sealedthis 30th day of July, A. D. 1914.05 I

- Henry-Van Aredele, v I (Se'ai) Acting Gommissionep of Patents, 

